In dentistry, it is now widely accepted practice to use unit dose cartridges for dispensing dental materials to dental patients. These cartridges are designed to contain a small dose of material that can be applied to a single patient. These single patient dose cartridges provide many advantages over other bulk dispensing techniques. For example, the application of dental filling material with a single dose dental cartridge permits a cavity to be filled from the inside out. This effectively prevents voids and the entrapment of air, which could compromise the integrity of the filling. Additionally, the use of a unit dose cartridge helps to prevent the risk of possible cross-contamination from one dental patient to the next. A single patient dose cartridge is used only on one patient and thereafter discarded. The single patient dose cartridge is also a convenience for the dentist. This saves the dentist valuable time. Also, the single patient dose cartridge is the only practical means, when made of an opaque actinic material, to apply light activated dental materials.
The cartridges are typically dispensed with the use of a syringe gun having a mechanical advantage. One example of a syringe used in conjunction with a cartridge is disclosed in U.S. Pat. No. 3,581,399 entitled "Composite Resin Filling Syringe and Technique" issuing to Dragan on Jun. 1, 1971. Another example of such a gun used with dental cartridges is disclosed in U.S. Pat. No. 4,198,756 entitled "Manual Extruder" issuing to Dragan on Apr. 22, 1980. Yet another syringe gun is disclosed in U.S. Pat. No. 4,384,853 entitled "Ejector Holder for Capsule Like Cartridge" issuing to Welsh on May 24, 1983.
A type of cartridge that is used in the syringe guns identified above is disclosed in U.S. Pat. No. 4,330,280 entitled "Ejector Holder for Capsule Like Cartridges" issuing to Dougherty et al on May 18, 1982. Yet another type of cartridge is disclosed in U.S. Pat. No. 4,963,093 entitled "Dental Syringe Tip and Syringe Holder Therefor" issuing to Dragan on Oct. 16, 1990, which is herein incorporated by reference. These cartridges typically have a reservoir body portion sealed at one end with a plug or piston, and an angularly disposed nozzle through which the dental material is discharged. The cartridges being disposable, are typically supplied in quantity. They are often packaged loosely together. To prevent contamination of the dental material contained therein, a sealing cap is placed over the discharge nozzle.
In manufacturing, the placement of the cap is often accomplished by a manual operation that requires some degree of dexterity to perform rapidly. The placement of the sealing cap may be accomplished by automation, but at a considerable expense. It is common practice to use color coding for these sealing caps to distinguish between colors or shades of colors of the dental material contained in the cartridge. However, as the numbers of colors and shades of dental material made available to the dentist increase, providing a successful color coding scheme for the sealing caps that can distinguish between the many colors and shades, is impractical. Additionally, when the loose cartridges are sealed with sealing caps, they must then be counted and repackaged for shipment to the dentist. This results in an additional step in the manufacturing process. Therefore, there is a need to improve the packaging of single patient dose cartridges to increase efficiencies and thereby reduce cost to the dentist, while at the same time providing a convenient package and system which the dentist can use for dispensing composite filling material in numerous shades and colors, resulting in improved dental care being provided to the patient.